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1.
Food security exists when people have access to sufficient, safe and nutritious food at all times to meet their dietary needs. The natural resource base is one of the many factors affecting food security. Its variability and decline creates problems for local food production. In this study we characterize for sub-Saharan Africa vegetation phenology and assess variability and trends of phenological indicators based on NDVI time series from 1982 to 2006. We focus on cumulated NDVI over the season (cumNDVI) which is a proxy for net primary productivity. Results are aggregated at the level of major farming systems, while determining also spatial variability within farming systems. High temporal variability of cumNDVI occurs in semiarid and subhumid regions. The results show a large area of positive cumNDVI trends between Senegal and South Sudan. These correspond to positive CRU rainfall trends found and relate to recovery after the 1980??s droughts. We find significant negative cumNDVI trends near the south-coast of West Africa (Guinea coast) and in Tanzania. For each farming system, causes of change and variability are discussed based on available literature (Appendix A). Although food security comprises more than the local natural resource base, our results can perform an input for food security analysis by identifying zones of high variability or downward trends. Farming systems are found to be a useful level of analysis. Diversity and trends found within farming system boundaries underline that farming systems are dynamic. 相似文献
2.
Victorian farmers have experienced significant impact from climate change associated with drought and more recently flooding. These factors form a convergence with a complex of other factors to change production systems physically; and farmers’ decision making is variously described as adaptive or maladaptive to these drivers of change. Recently updated State Government policies on farming, climate and water have immediate and long term implications for food production systems but are not readily interpreted at a local scale. Further, peak oil and energy security are only partially integrated into either climate or water policy discourse. In effect, despite some far-sighted words about the meaning of climate change, uncertainty is largely met with a ‘business as usual’ mantra. Farmer narratives are used to demonstrate their systemic and increasing vulnerability and likelihood of perverse outcomes. The Future Farming strategy and Our Water Our Future are briefly analyzed, as are potential implications of the rhetoric of newly elected conservative government. Using ideas from Bourdieu and Bhabha we suggest that the reliance on farmers being able to innovate and take up opportunities associated with the uncertainty of large scale changes in climate and energy availability are misguided. It is more likely that current policy directions entrench the values of the global market and its elite, leaving farmers locked-in to historical structural responses that will not be successful in the long-term and will diminish their ability to imagine radical and diverse ways of avoiding the maladaptive structures currently surrounding their production systems. 相似文献
3.
Beatrice I. Crona Patrik Rönnbäck Narriman Jiddawi Jacob Ochiewo Sam Maghimbi Salomão Bandeira 《Global Environmental Change》2009,19(2):227-239
Coastal cities in East Africa are growing rapidly and consequently there is a rapid increase in urban sewage production, putting added pressure on already strained treatment systems. As a result, peri-urban mangroves are receiving extensive amounts of sewage but very little is know as to the ecological and societal consequences of this. However, UNEP among others advocate the use of low-cost, natural sewage treatment technology whenever possible and mangroves have been suggested as useful second stage biofilters. Because of the high resource dependency in many peri-urban coastal communities in East Africa, it is imperative to investigate potential societal impacts on local communities using sewage impacted peri-urban mangroves. Consequently this paper aims to characterize stakeholder groups currently affected by sewage impacted mangroves and thus also map vulnerabilities across local users in relation to future initiatives to use mangroves as biofilters along the East African coast. As risk perception is an important part of vulnerability, and risk perception related to sewage and pollution in an African setting has been little studied, we also aim to contribute baseline data on risk perception related to pollution across peri-urban populations in Kenya, Tanzania and Mozambique. 相似文献
4.
Yue Li D. Conway Yanjuan Wu Qingzhu Gao S. Rothausen Wei Xiong Hui Ju Erda Lin 《Climatic change》2013,119(3-4):891-904
This study addresses the role of climate variability in the livelihoods of agricultural communities in Ningxia, Northwest China. Data sources comprise meteorological observations and official reports, complemented by questionnaires and focus group discussions designed around a livelihoods framework. Sample villages were located in three different agricultural systems: irrigated, mixed irrigated/grazing, and rainfed. Much of Ningxia is perennially dry and this is a significant limiting factor to agricultural production in the region, exacerbated by drought and buffered by irrigation mainly supplied from the Yellow River. Climate observations show stable temperatures from the 1950s to the 1980s followed by a positive trend (0.38°C/decade 1961–2010). Precipitation shows very modest trends and low decadal variability. Recent climate variability, particularly a drought from 2004–2006, was perceived to have had a significant effect on agricultural production and access to water, but it was not the only challenge respondents had faced. Susceptibility to drought was higher in the mixed irrigated and grazing and rainfed areas, due to farmers’ greater exposure to climatic hazards and because a higher proportion of their income originated from farming activities. Respondents were using a wide range of measures to retain and enhance soil moisture and maintain agricultural production. The discussion examines challenges in disentangling the role of climate within rapidly changing livelihood systems. 相似文献
5.
Environmental change is significantly altering hydrological systems worldwide, with substantial impacts for the people who live on floodplains and depend on rivers for their livelihoods and lifeways. Amazonia is a region significantly affected by these changes, particularly more severe flooding. This paper proposes a multi-scalar approach to vulnerability, applying it empirically to the analysis of household vulnerability to the 2011 flood—the second largest flood event along the Ucayali River in 30 years—in terms of exposure, impacts, and responses. Locally relevant indicators for assets, social identity, and social networks at the community and household levels are used to examine their role in shaping flood vulnerability, the interplay of community-level and household-level factors, and differential vulnerability across exposure, impacts, and responses to the same hazard event. We find that the most common impacts of severe flooding in rural Amazonia are on agriculture and that fishing is the dominant response strategy. This study suggests that covariate shocks, like floods, can have distinct idiosyncratic impacts and responses among households. We demonstrate that more integrated approaches to vulnerability analysis offer potential for better understanding differential vulnerabilities within populations as well as for drawing comparisons across hazard events and different settings. 相似文献
6.
Andrew Challinor Tim Wheeler Chris Garforth Peter Craufurd Amir Kassam 《Climatic change》2007,83(3):381-399
Africa is thought to be the region most vulnerable to the impacts of climate variability and change. Agriculture plays a dominant
role in supporting rural livelihoods and economic growth over most of Africa. Three aspects of the vulnerability of food crop
systems to climate change in Africa are discussed: the assessment of the sensitivity of crops to variability in climate, the
adaptive capacity of farmers, and the role of institutions in adapting to climate change. The magnitude of projected impacts
of climate change on food crops in Africa varies widely among different studies. These differences arise from the variety
of climate and crop models used, and the different techniques used to match the scale of climate model output to that needed
by crop models. Most studies show a negative impact of climate change on crop productivity in Africa. Farmers have proved
highly adaptable in the past to short- and long-term variations in climate and in their environment. Key to the ability of
farmers to adapt to climate variability and change will be access to relevant knowledge and information. It is important that
governments put in place institutional and macro-economic conditions that support and facilitate adaptation and resilience
to climate change at local, national and transnational level. 相似文献
7.
Conservation of land resources is a promising strategy for sustainable agricultural intensification in order to adapt dryland farming systems to climate, market and other stresses. At a local level, factors that drive the adoption of conservation measures operate and interact in specific ways. Linking our knowledge of the local specifications of these drivers to regional and global patterns of vulnerability can significantly enhance our understanding of land-based adaptation to global change. However, the factors that influence the adoption of conservation practices remain actively debated. Therefore, this study presents a meta-analysis of case studies that investigate the adoption of soil and water conservation measures, as an important approach to resource conservation. Synthesising 63 adoption cases in the drylands of western Africa, this meta-analysis reveals a multitude of factors that drive the adoption of soil and water conservation practices. The drivers differ strongly between particular practices and methods of analysis used in the case studies. Contributing to the broader debate on resource conservation, the findings highlight the adoption of soil and water conservation measures as an emergent property of farming systems. They demonstrate the need to better understand the socio-ecological foundation of adoption and the pathways along which adoption evolves in space and time. This study concludes with methodological principles to advance future research on the factors that drive the adoption of soil and water conservation measures as a pre-requisite of improving land-based adaptation efforts. 相似文献
8.
Water scarcity in northern China has been a topic of concern in China for many years, but the increased frequency and duration of “no-flow” events in the Yellow River in the 1990s created a flurry of recent activity in the academic and policy arenas. These low-flow events severely disrupted the supply of irrigation water for agriculture in the lower reaches of the Yellow River and posed a substantial threat to farmers’ livelihoods. Within a broader effort to assess farmers’ vulnerability to water shortages, this qualitative research focuses on the coping mechanisms and adaptive strategies adopted by farming households in three villages in Shandong Province (Ma, Ding, and Xing). With increasing water stress and other stresses from land degradation and lack of market access, farmers’ coping mechanisms have evolved, expanding from one-time adjustments to long-term adaptations, and switching focus from securing reliable water sources to improving irrigation efficiency and diversifying both on-farm and off-farm production. The three villages have different vulnerability profiles and adopted different patterns of adaptive processes that reveal the key roles played by community leaders and the early innovators. The research presented here contributes a temporal and dynamic dimension to the study of vulnerability which is largely missing from the current literature, and provides practical insights about how to improve farmers’ adaptive capacities in the face of water shortages in northern China. 相似文献
9.
Wetland regions are important components of the local climate, with their own characteristic surface energy and moisture
budgets. Realistic representation of wetlands, including the important vegetation component, may therefore be necessary for
more accurate simulations of climate and climate change. However, many land-atmosphere coupled models either ignore wetlands
or treat wetlands as bare, water-saturated soil, neglecting the vegetation present within wetland environments. This study
investigates the possible response of the mid-Holocene climate of North Africa to changes in orbital forcing, both with and
without the presence of wetlands. The location of these wetlands is guided by analysis of paleovegetation and wetland distribution.
In this study, the wetland regime in the land surface component of a climate model was modified to incorporate vegetation.
Field measurements have shown that vegetation affects water loss associated with evaporation (including transpiration) within
a wetland area. Comparisons between non-vegetated wetland and vegetated wetland revealed an increase in local albedo that
produced an associated decrease in net radiation, evaporation and precipitation in the vicinity of the wetlands regions. Based
on an analysis of the model surface water balance, the calculated area of mid-Holocene wetland coverage for North Africa closely
matches the observed. For the North African region as a whole, the effects of adding vegetation to the wetland produced relatively
small changes in climate, but local recycling of water may have served to help maintain paleo wetland communities.
Received: 16 March 1999 / Accepted: 17 May 2000 相似文献
10.
Increasing frequency, intensity and duration of severe weather events are posing major challenges to global food security and livelihoods of rural people. Agriculture has evolved through adaptation to local circumstances for thousands of years. Local experience in responding to severe weather conditions, accumulated over generations and centuries, is valuable for developing adaptation options to current climate change. This study aimed to: (i) identify tree species that reduce vulnerability of cropping systems under climate variability; and (ii) develop a method for rapidly assessing vulnerability and exploring strategies of smallholder farmers in rural areas exposed to climate variability. Participatory Rural Appraisal methods in combination with Geographical Information Systems tools and statistical analysis of meteorological data were used to evaluate local vulnerability to climate change and to investigate local adaptation measures in two selected villages in Vietnam, one of the countries most vulnerable to climate change. The low predictability of severe weather events makes food crops, especially grain production, insecure. This study shows that while rice and rain-fed crops suffered over 40 % yield losses in years of extreme drought or flood, tree-based systems and cattle were less affected. 13 tree species performed well under the harsh local climate conditions in home and forest gardens to provide income, food, feed and other environmental benefits. Thus, this research suggests that maintenance and enhancement of locally evolved agroforestry systems, with high resilience and multiple benefits, can contribute to climate change adaptation. 相似文献
11.
Much as development’s understanding of livelihoods became intertwined with notions of sustainability in the late 1990s, today livelihoods analysis is taking up the rise of resilience in the development and climate change adaptation communities of practice. The emergent concept of resilient livelihoods risks perpetuating problematic framings of both socio-ecological and livelihoods dynamics that limit the effectiveness of development and adaptation interventions. In this paper, I connect recent contributions to the livelihoods and socio-ecological resilience literatures to define resilient livelihoods as projects aimed at the achievement of well-being in a manner that preserves existing systems of meaning, order, and privilege. These projects (re)produce socio-ecologies, deeply human assemblages of socio-cultural and biotic elements. So framed, the idea of resilient livelihoods centers meaning, power, difference, and agency in both livelihoods and socio-ecological dynamics. It opens up new understandings of the character, sources, and importance of resilience in livelihoods, allows for the identification of new indicators of livelihoods fragility, points to previously-overlooked sources of potential livelihoods transformation and change, and suggests sites of productive engagement between development and adaptation interventions and transformation and change. 相似文献
12.
Since the late 1950s, production of both cash-crop cotton and food crops has increased immensely in the Malian cotton zone. The response of farmers to external incentives or obstacles has been swift. In an opportunistic way, farmers seem to seek immediate and maximum profits. This has been particularly evident with the boom in both cotton and food crop production after the devaluation of the CFA franc in January 1994. Such reactions support the idea that it is not only African pastoral production systems which are non-equilibrial and opportunistic, but that this also characterises farming communities. Furthermore, the agricultural development in the cotton zone is regularly said to cause serious environmental degradation mainly through deforestation and soil depletion. The paper questions this view. The environmental transformation taking place is analysed, but whether this transformation represents ‘degradation’ or ‘improvement’ is largely a normative question subject to the values and environmental perceptions of the individual actors. 相似文献
13.
Although sub-Saharan Africa does not contribute significantly to greenhouse gas emissions, significant adverse impacts of climate change are anticipated in this region. Countries in West Africa, which are heavily dependent on rain-fed agriculture, are projected to experience more frequent and intense droughts, altered rainfall patterns and increases in temperature through the end of this century. Changes in hydrology and temperature are likely to affect crop yields, thereby placing pressure on scarce resources in a region that is characterised by limited social, political, technical and financial resources. The success with which communities cope with the impacts of climate change is influenced by existing conditions, forces and characteristics which are peculiar to each of these communities. This paper assesses the preferred adaptation strategies during floods and droughts of males and females in three different occupations (farming, fishing, and charcoal production). Findings are based upon an analysis of focus group discussions and a ranking of preferred adaptation options in three communities in the Afram Plains of Ghana. Assessments of this nature should aid in the selection and implementation of adaptation options for communities and households, which is the level at which climate change adaptation is likely to occur in West Africa. 相似文献
14.
The Niger River is the third largest river in the African continent. Nine riparian countries share its basin, which rank all among the world’s thirty poorest. Existing challenges in West Africa, including endemic poverty, inadequate infrastructure and weak adaptive capacity to climate variability, make the region vulnerable to climate change. In this study, a risk-based methodology is introduced and demonstrated for the analysis of climate change impacts on planned infrastructure investments in water resources systems in the Upper and Middle Niger River Basin. The methodology focuses on identifying the vulnerability of the Basin’s socio-economic system to climate change, and subsequently assessing the likelihood of climate risks by using climate information from a multi-run, multi-GCM ensemble of climate projections. System vulnerabilities are analyzed in terms of performance metrics of hydroelectricity production, navigation, dry and rainy season irrigated agriculture, flooding in the Inner Delta of the Niger and the sustenance of environmental flows. The study reveals low to moderate risks in terms of stakeholder-defined threshold levels for most metrics in the 21st Century. The highest risk levels were observed for environmental flow targets. The findings indicate that the range of projected changes in an ensemble of CMIP3 GCM projections imply only relatively low risks of unacceptable climate change impacts on the present large-scale infrastructure investment plan for the Basin. 相似文献
15.
流域洪涝定量描述及江西省48a流域洪涝分析 总被引：1，自引：1，他引：1
分别对单站洪涝强度、流域集中期洪涝强度和流域汛期洪涝强度进行了定量描述。并对1951～1998年江西省5大流域的洪涝分别进行了比较分析,得出了各大流域近半世纪10大洪涝集中期、10大洪涝汛期和南北分片10大洪涝年。 相似文献
16.
17.
Evan D. G. Fraser 《Climatic change》2007,83(4):495-514
This paper builds on existing theory and proposes a framework to identify vulnerability to climate change in food systems by examining historic cases where common environmental problems caused famine. Cases presented are (1) Ireland’s Potato Famine, (2) El Niño induced famines during the Colonial period, and (3) Ethiopia between 1965 and 1997. Three factors stand out as common in each. Prior to each famine: (1) there were very few ways that people could obtain a living in the worst affected regions; (2) livelihoods in famine stricken communities came to depend on highly specialized agro-ecosystems that were sensitive to environmental change; (3) institutions failed to provide adequate safety nets to protect livelihoods from failure. This analysis suggests that vulnerability to climate change in food systems can be assessed by looking at agro-ecosystems, livelihoods and institutions. Local conditions, however, mean that ways of measuring these three factors will vary from place to place. As a result, direct comparisons are difficult. By conceptualizing these three variables as the axes of a three dimensional “vulnerability” space, it is possible to compare regions and look at trends over time by studying the paths through this “space” as traced by changes at the agro-ecosystem, livelihood, and institutional scale. 相似文献
18.
极端天气气候事件变化对荒漠化、土地退化和粮食安全的影响 总被引：1，自引：0，他引：1
土地是人类赖以生存的重要资源,在受气候变化影响的同时其状况变化也在气候系统中起着关键作用。IPCC最新发布的气候变化与土地特别报告（SRCCL）系统反映了关于荒漠化、土地退化、可持续土地管理、粮食安全和陆地生态系统碳通量方面的最新科学认知,并探讨了如何进行更加可持续性的土地利用和管理以应对与土地相关的气候变化问题。文中从极端事件变化及其影响的角度,结合SRCCL与其他相关文献,予以分析和总结。结果表明,在全球变暖的背景下,极端天气气候事件的变化已经并将继续影响荒漠化和土地退化进程并对粮食安全造成冲击;而土地对气候系统的反馈作用,又会加剧气候变化并提高极端事件发生的概率和严重程度。面对气候变化尤其是极端事件给土地带来的巨大压力,必须坚持可持续的土地管理,通过减少包括土地和粮食系统在内的所有行业的排放,才有可能实现到21世纪末将全球平均升温控制在相对工业化前水平2℃以内的目标,以减轻气候变化对土地和粮食系统的负面影响。 相似文献
19.
Robin T.CLARK Xiquan DONG Chang-Hoi HO Jianhua SUN Huiling YUAN Tetsuya TAKEMI 《大气科学进展》2021,38(12):1977-1979
Throughout vast areas of Asia, the summer of 2020 was extraordinarily wet. After an exceptionally wet May in North-east India and Bangladesh, excessive rainfall hit at least 10 provinces in central and southern China in June and July, caus-ing extensive flooding in many rural and urban locations. Long standing rainfall, lake and river level records were con-sequently broken in several parts of the region with the Yangtze-Huaihe river valleys, particularly badly impacted, with con-sequential economic losses. Floods and landslides also affected parts of Japan with at least one location in Kumamoto province even experiencing a record-breaking 1000 mm of rainfall in just 3 days in early July. The 2020 wet season in South Korea was also exceptionally long, lasting 54 days, compared to their more usual 32. 相似文献
20.
Robin T.CLARK Xiquan DONG Chang-Hoi HO Jianhua SUN Huiling YUAN Tetsuya TAKEMI 《大气科学进展》2021,38(12):1977-1979
Throughout vast areas of Asia, the summer of 2020 was extraordinarily wet. After an exceptionally wet May in North-east India and Bangladesh, excessive rainfall hit at least 10 provinces in central and southern China in June and July, caus-ing extensive flooding in many rural and urban locations. Long standing rainfall, lake and river level records were con-sequently broken in several parts of the region with the Yangtze-Huaihe river valleys, particularly badly impacted, with con-sequential economic losses. Floods and landslides also affected parts of Japan with at least one location in Kumamoto province even experiencing a record-breaking 1000 mm of rainfall in just 3 days in early July. The 2020 wet season in South Korea was also exceptionally long, lasting 54 days, compared to their more usual 32. 相似文献